LT275/70R18 · LT-metric truck · Overview
LT275/70R18 tyre pressure
- Size
- LT275/70R18
- Class
- LT-metric truck
- Planning PSI
- 56
- Planning bar
- 3.86
LT275/70R18
56 psi / 3.86 bar
386 kPa · estimates for this size class
LT275/70R18 · 56 psi · 3.86 bar · 386 kPa — estimates. Placard wins.
LT275/70R18 is a LT-metric truck size (275 mm section, 70 % aspect, 18-inch rim). A planning cold figure around 56 psi / 3.86 bar / 386 kPa is a starting map, not a second factory sticker. TPMS typically warns near 42 psi (about 25% below a 56 psi target). That is already a soft tyre. LT-metric sizes print a load range. The vehicle door sticker, not the LT sidewall maximum, is still the operating pressure.
What LT275/70R18 means
Read LT275/70R18 as width / aspect R rim. Nothing in the size string is a pressure. Pressure lives on the car, not moulded as 205 or 55.
Plus-size LT 18-inch. Rim diameter 18 in; section 275 mm. Estimates on this page assume a typical load index for the LT-metric truck class.
Estimated LT275/70R18 pressure by load
Load moves the rear first on a LT-metric truck. If the factory placard already has a laden column, use that — not this sketch for LT275/70R18.
| Condition | Front (est.) | Rear (est.) |
|---|---|---|
| Driver only / unladen | 56 psi / 3.86 bar / 386 kPa | 59 psi / 4.07 bar / 407 kPa |
| Typical occupancy | 56 psi / 3.86 bar / 386 kPa | 60 psi / 4.14 bar / 414 kPa |
| Payload / towing (sketch) | 57 psi / 3.93 bar / 393 kPa | 67 psi / 4.62 bar / 462 kPa |
PSI, bar and kPa
1 bar ≈ 14.5 psi; 1 psi ≈ 6.89 kPa. Planning midpoint for LT275/70R18: 56 psi = 3.86 bar = 386 kPa.
| PSI | Bar | kPa |
|---|---|---|
| 44 | 3.03 | 303 |
| 46 | 3.17 | 317 |
| 50 | 3.45 | 345 |
| 52 | 3.59 | 359 |
| 53 | 3.65 | 365 |
| 54 | 3.72 | 372 |
| 55 | 3.79 | 379 |
| 56 | 3.86 | 386 |
| 57 | 3.93 | 393 |
| 58 | 4.00 | 400 |
| 59 | 4.07 | 407 |
| 60 | 4.14 | 414 |
| 61 | 4.21 | 421 |
| 62 | 4.27 | 427 |
| 63 | 4.34 | 434 |
| 64 | 4.41 | 441 |
| 65 | 4.48 | 448 |
| 66 | 4.55 | 455 |
| 67 | 4.62 | 462 |
| 68 | 4.69 | 469 |
| 80 | 5.52 | 552 |
Placard versus sidewall
The sidewall of a LT275/70R18 may say 51 psi or 350 kPa. That is a carcass maximum. Operating pressure is the tyre-information placard on the driver’s door pillar.
Cars often seen on LT275/70R18
These catalogue models are often seen on LT275/70R18 or a close OEM neighbour. Open the vehicle chart for axle-specific PSI and bar.
How to set LT275/70R18
- Measure before the school run, not after the motorway.
- Write LF / RF / RR / RL. Do not keep LT275/70R18 numbers in your head.
- Add air in short bursts toward the placard, using 56 psi only as a map.
- If one LT275/70R18 is 4 psi down, hunt for a nail before you blame the weather.
- Log date, ambient temperature and the four readings.
Temperature drift
Roughly 1 psi per 5–6 °C. The table uses 56 psi as a 20 °C baseline for LT275/70R18.
| Ambient | Gauge | Bar | kPa | Note |
|---|---|---|---|---|
| −5 °C (hard frost) | 53 psi | 3.65 bar | 365 kPa | Gauge reads low; do not overfill once warm |
| 0 °C | 54 psi | 3.72 bar | 372 kPa | Gauge reads low; do not overfill once warm |
| 8 °C (UK winter morning) | 55 psi | 3.79 bar | 379 kPa | Gauge reads low; do not overfill once warm |
| 20 °C (set cold here) | 56 psi | 3.86 bar | 386 kPa | Baseline for this size sketch |
| 30 °C | 58 psi | 4 bar | 400 kPa | Do not bleed a hot LT275/70R18 |
| 38 °C (heatwave tarmac) | 59 psi | 4.07 bar | 407 kPa | Do not bleed a hot LT275/70R18 |
A cheap gauge and a monthly habit will do more for a set of LT275/70R18 than nitrogen upsells.
Questions about LT275/70R18
Is the sidewall number correct for LT275/70R18?
No. Sidewall PSI or kPa is a maximum for the carcass. Operating pressure is the door-pillar placard.
Can I run LT275/70R18 at a lower pressure for comfort?
Not as a habit. A soft LT275/70R18 cooks the shoulders and dulls steering. Keep load index and stay on the placard.
What is LT275/70R18 in bar?
56 psi is 3.86 bar. Add a tenth of a bar if the placard’s laden column is higher, which is common on vans that wear this size.
Should I bleed pressure after a motorway run?
No. Heat raises the gauge. Set cold only. Bleeding a hot tyre leaves it low the next morning.
When does TPMS warn on LT275/70R18?
Direct TPMS typically flags about 25% below target — near 42 psi if you were aiming at 56. Fill to the sticker, not to the lamp.
Handbook: placard · bar vs PSI · cold inflation · all sizes